Ineed on how to find the number 3 and 4

The number of calories you burn depends on your weight. a 110-pound person burns 163 calories during 30 minutes of tennis. find the number of calories that a 190-pound person would burn during the same activity, assuming they burn calories at the same rate.

Let f(x) = 5/x and g(x)=2x2+5x. what two numbers are not in the domain of f o g

Is the number 128.439 a rational number